New language features
---------------------
o Unlimited character constant size.
There is no longer any limit to the size of character constants,
e.g. 'acdefghijk' creates the bignum 0x61636465666768696a6b.

function.
o typeof(X) can now be used as a type.
The main use case is in macros, but it might be useful for other
things as well (as an example in a typedef).
typedef typeof(Val.true)|typeof(Val.false) bool;
typeof, when used like this, behaves very much like the C++
decltype() expression.

o ** operator added. It's exponentiation and works with most
combination of numerical types (int,float,Gmp.mpq,Gmp.mpf,Gmp.mpz)
`** and ``** operator overloading functions added.
This introduces one incompatible change: Previously the "pow"
function called a "_pow" function in the first argument if it was an
object. It has now been changed to also use `** (or, rather, pow()

o Anonymous class definitions are now always expressions.
o Function local class definitions are now statements
(and not expressions). This means that there is no longer
any need to terminate them with a semicolon.

o Extended sscanf %O
sscanf() is now able to parse all base types that sprintf %O can
output. It can now also parse most literal constants pike accepts,
including integers prefixed with 0x and 0b, and floating point
numbers in scientific notation.

as any other method. Previously it would stop reading the body and
it was up to the caller to read enough data from the socket and
combine with already read data.
Setting "connection" header in the "extra_heads" to Request object
method response_and_finish() will now control if keep-alive should be
used or not. Otherwise it will be decided by the clients request
headers, as previously.
The headers "content-type", "content-range", "content-length",
"server", "date" and "last-modified" will not be added or
overwritten if provided in the "extra_heads".
Header names in "extra_heads" will not have their case modified.

o Sql.Sql is no longer a wrapper class, but a function.
The wrapper class has been obsoleted by introduction of the
new base class __builtin.Sql.Connection. Note that it is
still possible to use Sql.Sql as the type of connection objects.

o Gz.crc32 and Nettle.crc32c now only return positive results.
o glob() has changed.
The main incompatibilities are that [ and \ are now special
characters in the pattern, and if you check the return value against
1 instead of checking if it's true, and use an array as the first
argument you will have to change your code.
This is in order to extend the glob function to cover what
'standard' glob functions do:
glob() now accepts quotes (\* to match a single *, as an example)
and handles ranges ([abc] for a, b or c, [a-z0-9] for a single
character between a and z or 0-9
You can also negate a range using ^ or ! ([^a-zA-Z] as an example).
When the first argument (the pattern) to glob is an array, glob now
returns which pattern in the array matched.
o hash() has been changed to use siphash. The old hash function is
available under the name hash_8_0(). Note that this is not a
cryptographic hash function.
o Stdio.UDP()->send() no longer throws errors on EMSGSIZE and EWOULDBLOCK.
o If a thread exits with by throwing, the thrown value is propagated to wait().
o String.trim_all_whites() renamed String.trim().

o Floats are no longer by default sorted before added. This may reduce
the precision but increases the speed of adding large number of
floats by a factor of 500. Applications handling floats with large

o Parser.Markdown
o Crypto.Checksum
This module collect non-cryptographic checksums. Support for crc32,
adler32 and Castagnoli CRC (CRC32C).
NB: In the future these may be amended to support the Crypto.Hash API.

o predef::gc()
gc() called with a weak mapping as argument now removes weak references
that are only held by that mapping.
o ADT.Heap
- An indirection object ADT.Heap.Element has been added to make it
possible to optimize several heap operations.
- Added low_pop().
o Crypto & Nettle
- Added Curve25519 and EdDSA25519.
o Filesystem.Monitor
The filesystem monitoring system now uses accelleration via
Inotify et al.
o Gmp
- mpf is now implemented using gmpf if the library is available.
- Improved support for GMP 5.0 and later.
o GTK2
Multiple runtime fixes.
o JOSE (JSON Object Signing and Encryption)
Some low-level API support has been added to the Crypto and Web
modules to support parts of RFC 7515 - 7520.
o MasterObject
- Protect against the same file being compiled concurrently
in multiple threads.
- cast_to_program() and cast_to_object() should now be thread safe.

default. random_string() and random() now get their data directly
from the operating system random generator, i.e. /dev/urandom on
most unixen. This is about half the speed compared with the
random_string function in Pike 8.0, but is now as secure as the
system random generator.

- Random.Interface
This is not actually a generator, but an interface class that is
inherited into all the other generators. It contains code that can
turn the output from the random_string method into random numbers
with different limits without introducing bias. It also contains
code for all the different variants of random() on different
types. This is currently not possible to implement in Pike code,
as the typing is too complicated and it is not possible to access
private/protected _random methods in objects.
- Random.System
This generator maps directly on top of the system random
generator. This is the default generator used for random() and
random_string().
- Random.Deterministic

Objects implementing the _random lfun now get two arguments, the
current random_string() and random() functions. This is convenient
for C-level functions that doesn't have to look up functions
themselves. Note that it is possible for a user to replace these
with non-conforming functions (returning values of the wrong type,
strings of the wrong length or shift size, and values outside the
given range) or even non-functions.
All code in Pike that uses random now uses the current random
functions (though in some cases fixed at object creation). This
allows for repeatable results if the random functions are replaced
with a deterministic random generator, such as
Random.Deterministic. Example:
Random.Deterministic rnd = Random.Deterministic( seed );
add_constant( "random_string", rnd->random_string );
add_constant( "random", rnd->random );

- _sprintf() improvements: Thread.Mutex now prints the ID of the thread
holding the lock, and thread IDs are shown as hexadecimal numbers.
- Thread.Farm now supports a callback for thread creation and termination
for the purpose of tracking thread names.

C-level API changes
-------------------
o The contract for functions is now changed so that a function is no
longer required to clean the stack. The topmost value of the stack
will be regarded as the return value and the rest of the items on
the stack, compared to before the function arguments were pushed,
will be popped and discarded. Efuns still have to clean their stack
as previously.

o The preprocessor has been converted into a cmod, and been modified
to use more standard Pike datatypes.
o The preprocessor-specific hashtable implementation has been removed.
o The gdb_backtraces() function is now available also --without-debug.
o There's now support to block mapping hashtables from being shrunk
on map_delete().

o guaranteed_memset() is replaced with secure_zero() which fills a
buffer with zero. On x86 SSE2 is used to zero the memory without
loading it into the CPU cache, as this function is typically used
before calling free() on memory with cryptographic key data.